public class Third {
	public static void main(String[] args) {
	System.out.println(getSJXarea(3,4));
	System.out.println(getZFXarea(2));
	System.out.println(getCfXarea(5,6));
	}
	public static double getSJXarea(double a ,double b){
	double result=a*b*0.5;
	return result;
	}
	public static double getZFXarea(double a){
	double result=a*a;
	return result;
	}
	public static double getCfXarea(double a ,double b){
	double result=a*b;
	return result;
	}
}